Surface-modified fluorine-containing resin molded article

ABSTRACT

PCT No. PCT/JP95/01276 Sec. 371 Date Dec. 19, 1996 Sec. 102(e) Date Dec. 19, 1996 PCT Filed Jun. 26, 1995 PCT Pub. No. WO96/01287 PCT Pub. Date Jan. 18, 1996To provide a fluorine-containing resin molded article surface-modified by irradiating, onto a surface thereof, a laser beam having a wavelength of 150 to 370 nm through a basic solution, preferably an aqueous basic solution. The surface-modified fluorine-containing resin molded article is excellent in adhesion to not only organic materials but also metals.

TECHNICAL FIELD

The present invention relates to techniques for surface modification ofa fluorine-containing resin molded article by irradiation of a laserbeam to enhance its adhesion, printing properties and affinity withother compounds.

BACKGROUND ART

A fluorine-containing resin is excellent in heat resistance, chemicalresistance, weather resistance and the like, and is used widely in themedical, electronic and chemical fields, field of precision instrument,etc.

Since the fluorine-containing resin, however, has water- andoil-repelling property and small surface activating energy, thefluorine-containing resin has very poor adhesion, difficulty ofproduction of a composite material and inferior printing properties.

Therefore various techniques for modifying a surface of afluorine-containing resin molded article have been studied, and therehave been proposed chemical etching treatment by means of a liquidammonia/sodium solution or a sodium/naphthalene complex; coronadischarge treatment; plasma discharge treatment; and the like.

Further, surface modification by pulse-irradiation of an excimer laserbeam having a wavelength ranging from 95 to 200 nm was proposed(JP-B-57143/1991). However, that method is such that afluorine-containing resin molded article is pulse-irradiated in the airwith the excimer laser beam having a wavelength ranging from 95 to 200nm, and thus, its adhesion to an adhesive, printing ink, paint or thelike is improved, but is not sufficient. Also though it is known thatnearly the similar improvement in adhesion is obtained by irradiating alaser beam in an atmosphere of inorganic compound such as hydrazine gas(Niino, Yabe et al., "Contributions II to The 65th Spring Meeting ofJapan Chemical Society" (1993), p252), when such a gas is used, a vacuumvessel is required, which makes a cost of an equipment high. Inaddition, hydrazine has toxicity and explosiveness and there is aproblem with its handling.

In addition to the above-mentioned methods, there is known a method forsurface-modifying an acrylic resin by irradiating a laser beam in anatmosphere of gaseous or liquid nitrogen-containing compound(JP-A-222223/1993). However, that patent publication does not indicateany concept of making the atmosphere basic in the surface modificationof a fluorine-containing resin molded article, and says that theatmosphere used is preferably in gaseous form rather than in liquidform.

It is an object of the present invention to solve the above-mentionedproblems of conventional methods and to provide a surface-modifiedfluorine-containing resin molded article which has enhanced adhesion notonly to organic materials such as an adhesive, printing ink and paintbut also to metals.

DISCLOSURE OF THE INVENTION

The present invention relates to a surface-modified fluorine-containingresin molded article obtained by irradiating its surface with a laserbeam having a wavelength of 150 to 370 nm through a basic solution.

It is preferable that the above-mentioned basic solution is an aqueousbasic solution.

It is preferable that a pKb of the above-mentioned aqueous basicsolution is not more than 5.

It is preferable that the pKb of the above-mentioned aqueous basicsolution is from 4 to 0.1.

It is preferable that the above-mentioned aqueous basic solution is anaqueous solution of a quaternary phosphonium compound or quaternaryammonium compound represented by the formula:

    (R.sup.1).sub.3 Y.sup.⊕ R.sup.9 ·X.sup.⊖

wherein R¹ is an alkyl group having 1 to 20 carbon atoms, R⁹ is an alkylgroup having 1 to 20 carbon atoms or an aralkyl group having 7 to 20carbon atoms, X is an anion such as halide, hydroxylate, alkoxylate,carboxylate, phenoxide, sulfonate, sulfate, sulfite or carbonate, Y isnitrogen atom or phosphorus atom; a quaternary ammonium compoundrepresented by the formula:

    (R.sup.1).sub.3 N.sup.⊕ R.sup.10 N.sup.⊕ (R.sup.1).sub.3 ·2X.sup.⊖

wherein R¹ and X are the same as above, R¹⁰ is an alkylene group having1 to 21 carbon atoms or a phenylenedialkylene group having 8 to 12carbon atoms; or a quaternary ammonium compound represented by theformula: ##STR1## wherein X is the same as above, R¹¹ is an alkyl grouphaving 1 to 24 carbon atoms or an aralkyl group having 7 to 20 carbonatoms.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an electron microscopic photograph (×5,000) showing a state ofa surface of a PTFE sheet before irradiation of a laser beam in Example1.

FIG. 2 is a scanning electron microscopic photograph (×5,000) showing astate of a surface of a PTFE sheet after irradiation of a laser beam inExample 2.

BEST MODE FOR CARRYING OUT THE INVENTION

As a fluorine-containing resin molded article to be surface-modified inthe present invention, there are exemplified molded articles ofpolytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVdF),tetrafluoroethylene-perfluoro(alkyl vinyl ether) copolymer (PFA),ethylene-tetrafluoroethylene copolymer (ETFE),ethylene-chlorotrifluoroethylene copolymer (ECTFE) and the like. Thosepolymers may contain a heat resistive resin, for example, polyamideimide (PAI), polyimide (PI), polyphenylene sulfide (PPS), polyethylenesulfide (PES) or the like in an amount of not more than about 50% byweight. Also to those polymers may be added a known additive orprocessing aid such as filler, plasticizer, stabilizer, lubricant,extender, pigment, dye, heat resistance improver, flame retarder,anti-oxidant, weather resistive agent, light absorber, surfactant,cross-linking agent, anti-fogging agent, moisture-proof agent andelasticity improver.

A shape of the molded article is not limited particularly, and variousshapes such as film, tape, sheet, plate, rod and fiber can be treated. Amethod of molding also is not limited particularly. There can beemployed known molding methods such as melt-extrusion method, castingmethod, compression method and calendering method.

According to the present invention, such a fluorine-containing resinmolded article is irradiated with a laser beam through a basic solution.

A wavelength range of the laser beam to be irradiated is from 150 to 370nm, preferably from 193 to 308 nm. A laser beam having a wavelengthexceeding 370 nm has an effect of only causing optical deterioration andthermal deterioration of the synthetic resin molded article. Also alaser beam having a wavelength less than 150 nm is not known as a lightsource usable for industrial use. As lasers irradiating a laser beamhaving the above-mentioned wavelength range, there are for example, anexcimer laser (ArF(193 nm), KrCl(222 nm), KrF(249 nm), XeCl(308 nm) orXeF(350 nm)), a gas laser (Ar(351.1 nm), (363.8 nm), Kr(350.7 nm),(356.4 nm) or N₂ (337.1 nm)), an Nd-YAG laser (wavelength converted to1/4(266 nm)), a semiconductor laser (ZnS(about 340 nm)), a dye laser(cumulene) and the like. From a point of easy handling for industrialuse and from safety point of view, a solid laser is preferable, andparticularly, easily available YAG laser which has a wavelengthconverted to 1/4 or 1/3 is preferable.

Irradiation of a laser beam may be pulse-irradiation or continuousirradiation. Irradiation conditions vary depending on lasers. In case ofpulse irradiation, an energy per 1 pulse is from 1 to 1,000 mJ, and thenumber of pulses is from 100 to 50,000 pulses, and in case of continuousirradiation, an output of a laser is from 10 mW to 10 W. The totalirradiation energy thereof is conditioned on 50 J/cm² to 500 J/cm².

An important feature of the present invention is to carry outirradiation of the laser beam through a basic solution, preferably anaqueous solution thereof but not in the air. As the basic solution,there is, for example, an aqueous solution of an inorganic basiccompound such as NH₄ OH or a solution of an organic basic compound.

As the organic basic compound, there is, for example, an organicphosphorus compound or organic amine compound represented by the formula(I): ##STR2## wherein Y is nitrogen atom or phosphorus atom, R¹, R² andR³ are the same or different and are hydrogen atom or an alkyl grouphaving 1 to 20 carbon atoms, each may be a cycloalkyl group, two of R¹,R² and R³ may be bonded to form a ring (when the ring is formed, Y inthe above-mentioned formula is nitrogen atom), or an organic aminecompound represented by the formula (II): ##STR3## wherein R⁴, R⁵, R⁶and R⁷ are the same or different and each is hydrogen atom or an alkylgroup having 1 to 6 carbon atoms, two of R⁴ and R⁶ and/or of R⁵ and R⁷may be bonded to form a ring, R⁸ is an alkylene group having 1 to 21carbon atoms.

Also there may be used inorganic or organic acid salts thereof (in caseof those organic or inorganic acid salts, Y in the above-mentionedformula is nitrogen atom).

Further, there is a quaternary phosphonium compound or quaternaryammonium compound represented by the formula (III):

    (R.sup.1).sub.3 Y.sup.⊕ R.sup.9 ·X.sup.63     (III)

wherein Y and R¹ are the same as above, R⁹ is an alkyl group having 1 to20 carbon atoms or an aralkyl group having 7 to 20 carbon atoms, X is ananion such as halide, hydroxylate, alkoxylate, carboxylate, phenoxide,sulfonate, sulfate, sulfite or carbonate; a quaternary ammonium compoundrepresented by the formula (IV):

    (R.sup.1).sub.3 N.sup.⊕ R.sup.10 N.sup.⊕ (R.sup.1).sub.3 ·2X.sup.⊖                                (IV)

wherein R¹ and X are the same as above, R¹⁰ is an alkylene group having1 to 21 carbon atoms or a phenylenedialkylene group having 8 to 12carbon atoms; a quaternary ammonium compound represented by the formula(V): ##STR4## wherein X is the same as above, R¹¹ is an alkyl grouphaving 1 to 24 carbon atoms or an aralkyl group having 7 to 20 carbonatoms; a quaternary ammonium compound represented by the formula (VI):##STR5## wherein R¹¹ and X are the same as above; a quaternary ammoniumcompound represented by the formula (VII): ##STR6## wherein R⁹ and X arethe same as above, R¹² is an alkyl or cycloalkyl group having 1 to 20carbon atoms or an aralkyl group having 7 to 20 carbon atoms, R¹³ ishydrogen atom, an alkyl or cycloalkyl group having 1 to 12 carbon atoms,an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to15 carbon atoms, an ether residue having 1 to 12 carbon atoms, hydroxyl,carbonyl, an alkoxycarbonyl group, an acyl group or a heterocyclic grouphaving at least nitrogen atom and/or sulfur atom, R¹⁴ and R¹⁵ are thesame or different and each is hydrogen atom or a lower alkyl grouphaving 1 to 4 carbon atoms; a quaternary ammonium compound representedby the formula (VIII): ##STR7## wherein X is the same as above, R¹⁶ isan alkyl group having 1 to 20 carbon atoms; or a quaternary ammoniumcompound represented by the formula (IX): ##STR8## wherein R¹⁶ and X arethe same as above.

Among them, the compounds represented by the formulae (Ill), (IV) and(VI) are preferable.

Examples of the formulae (I) and (II) are organic amine compounds suchas methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine,triethylamine, butylamine, dimethyldodecylamine, ethylenediamine andN,N,N',N'-tetramethyltrimethylenediamine; and organic phosphoruscompounds such as ethylphosphine, dimethylphosphine, diethylphosphine,trimethylphosphine and triethylphoshine. Examples of the formulae (III)and (IV) are quaternary ammonium compounds such as tetramethylammoniumhydroxide, tetrabutylammonium fluoride, vinyltrimethylammoniumhydroxide, tetraheptylammonium chloride, tetrabutylammonium stearate,tetramethylammonium chloride, distearyldimethylammonium chloride,methyltrioctylammonium oxalate, benzyltrioctylammonium chloride,trimethylbenzylammonium chloride, triethylbenzylammonium chloride,dimethyldodecylbenzylammonium chloride, triethylbenzylammonium bromide,myristylbenzyldimethylammonium chloride, dodecyltrimethylammoniumchloride, coconuttrimethylammonium chloride, cetyltrimethylammoniumchloride, stearyltrimethylammonium chloride, distearyldimethylammoniumchloride, N-methyltriethanolammonium chloride, tetrabutylammoniumhydroxide, 1,4-phenylenedimethylene-bistrimethylammonium dichloride and1,4-phenylenedimethylene-bistriethylammonium dichloride; and quaternaryphosphonium compounds such as tetrabutylphosphonium bromide,tetrabutylphosphonium iodide, tetramethylphosphonium acetate,tetrabutylphosphonium hydroxide and triphenylbenzylphosphonium bromide.Examples of the formula (VI) are quaternary ammonium compounds such as8-methyl-1,8-diazabicyclo(5.4.0)-7-undecenium chloride,8-methyl-1,8-diazabicyclo(5.4.0)-7-undecenium iodide,8-methyl-1,8-diazabicyclo(5.4.0)-7-undecenium hydroxide,8-methyl-1,8-diazabicyclo(5.4.0)-7-undecenium-methyl sulfate,8-ethyl-1,8-diazabicyclo(5.4.0)-7-undecenium bromide,8-propyl-1,8-diazabicyclo(5.4.0)-7-undecenium bromide,8-dodecyl-1,8-diazabicyclo(5.4.0)-7-undecenium chloride,8-dodecyl-1,8-diazabicyclo(5.4.0)-7-undecenium hydroxide,8-eicosyl-1,8-diazabicyclo(5.4.0)-7-undecenium chloride,8-tetracosyl-1,8-diazabicyclo(5.4.0)-7-undecenium chloride,8-benzyl-1,8-diazabicyclo(5.4.0)-7-undecenium chloride,8-benzyl-1,8-diazabicyclo(5.4.0)-7-undecenium hydroxide,8-phenethyl-1,8-diazabicyclo(5.4.0)-7-undecenium chloride and8-(3-phenylpropyl)-1,8-diazabicyclo(5.4.0)-7-undecenium chloride.Examples of the formula (VII) are quaternary ammonium compounds such as1,3-dimethyl-2-heptylimidazolium iodide, 1,3-dimethyl-2-nonylimidazoliumiodide, 1,3-dimethyl-2-undecylimidazolium iodide,1,3-dimethyl-2-heptadecylimidazolium chloride,1-dodecyl-2,3-dimethylimidazolium-p-toluene sulfonate,1-tetradecyl-2,3-dimethylimidazolium hydroxide,1-dodecyl-2-undecyl-3-methylimidazolium methyl sulfate and1-vinyl-2-methyl-3-dodecylimidazolium chloride. Examples of the formula(VIII) are quaternary ammonium compounds such as laurylpyridiniumchloride and hexadecylpyridinium chloride. Examples of the formula (IX)are quaternary ammonium compounds such as laurylisoquinolinium chloride.

As the basic solution used in the present invention, there areexemplified an aqueous solution of an inorganic basic compound or asolution of an organic basic compound. Examples of the aqueous solutionof the inorganic basic compound are the above-mentioned aqueous solutionof NH₄ OH and the like. Examples of the solutions of the organic basiccompound are aqueous or non-aqueous solutions of the above-mentionedorganic amine compound, organic phosphorus compound, quaternary ammoniumcompound and quaternary phosphonium compound (for example, solution ofalcohol such as methanol or ethanol). Also the above-mentioned basiccompounds may be used as they are when they are in the form of liquid.Among them, aqueous solutions of the quaternary ammonium compounds andquaternary phosphonium compounds are preferable from points of highbasicity and good handling property.

With respect to basicity of the basic solution, it is desirable that apKb of its aqueous solution is not more than about 5, preferably about 4to 0.1.

As a treating method, for example, the basic solution is filled in avessel made of quartz, and the fluorine-containing resin molded articleto be treated is completely dipped therein. The vessel is placed on amovable table, and the table is moved while the laser beam is irradiatedfrom the above to modify a desired region on a surface of thefluorine-containing resin molded article.

The surface-modified fluorine-containing resin molded article of thepresent invention not only has more enhanced adhesion to an adhesive,printing ink and paint but also can obtain good adhesion to metals.Therefore, in producing a fluorine-containing resin printed circuit forhigh frequency in an electronic industry, metal wiring can be provideddirectly on the circuit by pattern irradiation of the laser beam to thefluorine-containing resin molded article and then electroless plating ofa metal.

The present invention is explained in the following by means ofExamples, but is not limited thereto.

Example 1

A PTFE sheet (tradename Polyflon available from Daikin Industries, Ltd.)was placed in a quartz chamber filled with 5% by weight of aqueoussolution (pKb: 0.2) of tetramethylammonium hydroxide, and then after thechamber was sealed with a quartz plate, 2,000 pulses of a laser beamhaving a wavelength of 266 nm were irradiated by using an Nd:YAG laserwith an energy of 40 mJ/1 pulse/1.1 cm².

Surface condition of the obtained surface-modified PTFE sheet wasexamined with a scanning type electron microscope (SEM, ×5,000). FIG. 1is a photograph showing the surface condition before the irradiation ofthe laser beam, and FIG. 2 is a photograph showing the surface conditionafter the irradiation of the laser beam. It is seen from thosephotographs that surface roughness of the surface-modified PTFE sheet(FIG. 2) is enhanced as compared with the untreated sheet (FIG. 1).

Then the surface-modified PTFE sheet was plated with copper throughelectroless plating method under the following conditions.

The surface-modified PTFE sheet was washed with water, and thenactivated with an activating solution comprising palladium, tin andhydrochloric acid (0.5 g/liter of palladium, 12 g/liter of tin, 160g/liter of 36% hydrochloric acid). Then the sheet was washed with waterand dipped at 70° C. for 90 minutes in an electroless plating solutionof copper having pH of about 12 (CuSO₄ ·5H₂ O: 12 g/liter, 37% formalin:6 ml/liter, NaOH: 12 g/liter, EDTA (2 Na): 35 g/liter) to carry outelectroless copper plating.

Copper adhered to the whole surface of the copper plated PTFE sheet. Thesheet was then subjected to ultrasonic cleaning in water at roomtemperature for one minute. Copper on the surface where the laser beamwas not irradiated was easily peeled off, but the surface irradiatedwith the laser beam was not peeled off.

Furthermore, when the through hole was formed on the copper-plated PTFEsheet, there occurred no crack on the copper plating layer.

Example 2

A surface of a PTFE sheet was modified in the same manner as in Example1 except that 2,000 pulses of a laser beam was irradiated with an energyof 35 mJ/1 pulse/1.05 cm².

To examine hydrophilic property of the surface-modified PTFE sheet, acontact angle with water was measured. The measured advancing contactangle and receding contact angle were 80° and 35°, respectively, whichshowed the fact that the hydrophilic property of the sheet was enhanced.

In measurement of the contact angle, a water droplet of 1.5 mm indiameter was made with a microsyringe and was brought into contact witha surface of the surface-modified PTFE sheet to transfer the waterdroplet on the surface of the PTFE sheet. Then the sheet was inclinedslowly, and the contact angles at the side of an advancing direction anda receding direction of water droplet were measured as an advancingcontact angle and a receding contact angle, respectively, when the waterdroplet begins to slide.

Example 3

A sheet surface-modified under the same conditions as in Example 1 wassubjected to electroless nickel plating under the following conditions.

The surface-modified PTFE sheet was washed with water, and thenactivated with an activating solution comprising palladium, tin andhydrochloric acid (0.5 g/liter of palladium, 12 g/liter of tin, 160g/liter of 36% hydrochloric acid). Then the sheet was washed with waterand dipped at 70° C. for 90 minutes in an electroless plating solutionof nickel having pH of about 5 (Nickel chloride: 30 g/liter, aceticacid: 30 g/liter, sodium hypophosphite: 10 g/liter, ammonium acetate:38.8 g/liter) to carry out electroless nickel plating.

Nickel adhered to the whole surface of the nickel plated PTFE sheet. Thesheet was then subjected to ultrasonic cleaning in water at roomtemperature for one minute. Nickel on the surface where the laser beamwas not irradiated was easily peeled off, but the surface irradiatedwith the laser beam was not peeled off.

Example 4

An ETFE sheet (Thickness: 100 μm) (tradename Neoflon ETFE available fromDaikin Industries, Ltd.) was placed in a quartz chamber filled with 5%by weight of aqueous solution (pKb: 0.2) of tetramethylammoniumhydroxide, and then after the chamber was sealed with a quartz plate,2,000 pulses of a laser beam having a wavelength of 266 nm wereirradiated by using an Nd:YAG laser with an energy of 41 mJ/1 pulse/1.2cm².

Contact angles with water on the surface of the irradiated portion ofthe sheet were measured in the same manner as in Example 2. An advancingcontact angle and a receding contact angle were 81° and 43°,respectively.

Example 5

A PTFE sheet was surface-modified in the same manner as in Example 1except that basic solutions shown in Table 1 were used. The obtainedsurface-modified PTFE sheet was subjected to electroless copper platingin the same manner as in Example 1, and adhesion of the copper platinglayer was examined in the same manner as in Example 1. The results areshown in Table 1.

                                      TABLE 1                                     __________________________________________________________________________                         Peeling off of copper                                                                    Cracking on copper                                                 plating layer by                                                                         plating layer when                            Aqueous basic solution                                                                             ultrasonic cleaning                                                                      through hole was formed                       __________________________________________________________________________    Experiment                                                                          (CH.sub.3)NH.sub.3 OH                                                                   (pKb3.4)                                                                           No peeling off occurred                                                                  Very slight crack                             No. 5-1              on irradiated portion.                                                                   occurred.                                     Experiment                                                                          (CH.sub.3).sub.2 NH.sub.2 OH                                                            (pKb3.3)                                                                           No peeling off occurred                                                                  Very slight crack                             No. 5-2              on irradiated portion.                                                                   occurred.                                     Experiment                                                                          (CH.sub.3).sub.3 NHOH                                                                   (pKb4.3)                                                                           No peeling off occurred                                                                  Slight crack occurred.                        No. 5-3              on irradiated portion.                                   Experiment                                                                          (C.sub.2 H.sub.5).sub.3 NHOH                                                            (pKb3.3)                                                                           No peeling off occurred                                                                  Very slight crack                             No. 5-4              on irradiated portion.                                                                   occurred.                                     Experiment                                                                          Aqueous ammonia                                                                         (pKb4.8)                                                                           No peeling off occurred                                                                  Slight crack occurred.                        No. 5-5              on irradiated portion.                                   Experiment                                                                          (C.sub.4 H.sub.9).sub.4 NF                                                              (--) No peeling off occurred                                                                  No crack occurred.                            No. 5-6              on irradiated portion.                                   Experiment                                                                          (C.sub.4 H.sub.9).sub.4 POH                                                             (--) No peeling off occurred                                                                  No crack occurred.                            No. 5-7              on irradiated portion.                                   Experiment                                                                          8-Benzyl-1,8-                                                                           (--) No peeling off occurred                                                                  No crack occurred.                            No. 5-8                                                                             diazabicyclo(5.4.0)-7-                                                                       on irradiated portion.                                         undecenium chloride                                                     __________________________________________________________________________

Example 6

A PTFE sheet was surface-modified in the same manner as in Example 1except that a laser beam generated with a laser shown in Table 2 andhaving a wavelength shown in the same table was used.

The obtained surface-modified PTFE sheet was subjected to electrolesscopper plating in the same manner as in Example 1, and adhesion of thecopper plating layer was examined in the same manner as in Example 1.The results are shown in Table 2.

                  TABLE 2                                                         ______________________________________                                                                     Peeling off of                                                                copper plating                                                                layer by                                                Laser beam            ultrasonic                                              Laser   Wavelength (nm)                                                                             cleaning                                         ______________________________________                                        Experiment                                                                             Excimer   193           No peeling off                               No. 6-1  laser                   occurred on                                           (ArF)                   irradiated portion.                          Experiment                                                                             Nd-YAGX   355           No peeling off                               No. 6-2  1/3                     occurred on                                                                   irradiated portion.                          ______________________________________                                    

Comparative Examples 1 and 2

A surface of a PTFE sheet was modified in the same manner as in Example1 except that a laser beam was irradiated in an atmosphere shown inTable 3 but not through a basic solution.

The obtained PTFE sheet was subjected to electroless copper platingunder the same conditions as in Example 1. There occurred peeling off ofcopper easily or partially by the ultrasonic cleaning even on thesurface irradiated with the laser beam.

Comparative Example 3

After a PTFE sheet was put in a vacuum chamber made of quartz and thechamber was evacuated, ammonia gas was introduced until the pressurereaches 500 mmHg. Then a laser beam was irradiated in the same manner asin Example 1. The resulting PTFE sheet was subjected to electrolesscopper plating in the same manner as in Example 1. Copper even on theirradiated portion was peeled off easily by the ultrasonic cleaning.

                  TABLE 3                                                         ______________________________________                                                             Peeling off of copper                                                         plating layer by                                                 Atmosphere   ultrasonic cleaning                                      ______________________________________                                        Com.      Pure water     Peeling off occurred                                 Ex. 1                    easily.                                              Com.      Aqueous solution                                                                             Peeling off occurred                                 Ex. 2     of boric       easily.                                                        acid (5% by weight)                                                 ______________________________________                                    

INDUSTRIAL APPLICABILITY

According to the present invention, not only enhancement of adhesion toorganic materials but also provision of adhesion to metals, which couldnot be obtained hitherto by laser beam irradiation, can be made.

We claim:
 1. A surface-modified fluorine-containing resin molded articleobtained by irradiation of a laser beam having a wavelength of 150 to370 nm through a basic solution onto a surface of a fluorine-containingresin molded article.
 2. The surface-modified fluorine-containing resinmolded article of claim 1, wherein said basic solution is an aqueousbasic solution.
 3. The surface-modified fluorine-containing resin moldedarticle of claim 2, wherein a pKb of said aqueous basic solution is notmore than
 5. 4. The surface-modified fluorine-containing resin moldedarticle of claim 2, wherein a pKb of said aqueous basic solution is from4 to 0.1.
 5. The surface-modified fluorine-containing resin moldedarticle of claim 2, wherein said aqueous basic solution is an aqueoussolution of a quaternary phosphonium compound or quaternary ammoniumcompound represented by the formula:

    (R.sup.1).sub.3 Y.sup.⊕ R.sup.9 ·X.sup.⊖

wherein R¹ is an alkyl group having 1 to 20 carbon atoms, R⁹ is an alkylgroup having 1 to 20 carbon atoms or an aralkyl group having 7 to 20carbon atoms, X is an anion such as halide, hydroxylate, alkoxylate,carboxylate, phenoxide, sulfonate, sulfate, sulfite or carbonate, Y isnitrogen atom or phosphorum atom; a quaternary ammonium compoundrepresented by the formula:

    (R.sup.1).sub.3 N.sup.⊕ R.sup.10 N.sup.⊕ (R.sup.1).sub.3 ·2X.sup.⊖

wherein R¹ and X are the same as above, R¹⁰ is an alkylene group having1 to 21 carbon atoms or a phenylenedialkylene group having 8 to 12carbon atoms; or a quaternary ammonium compound represented by theformula: ##STR9## wherein X is the same as above, R¹¹ is an alkyl grouphaving 1 to 24 carbon atoms or an aralkyl group having 7 to 20 carbonatoms.